<i>Diverse moth assemblages show little response to light pollution in highly urbanized Hong Kong</i>

Title: Diverse moth assemblages show little response to light pollution in highly urbanized Hong Kong Abstract: Artificial light at night is a well-documented driver of insect declines in temperate regions, but its effect on tropical ecosystems remains poorly understood. In this study, we assessed the impact of both direct artificial light at night and skyglow on moth assemblages in Hong Kong, a highly urbanized tropical city with long-term light pollution exposure. Using both light and bait traps, we captured 725 moth species across nine sites which experienced direct artificial light at night and varied in their exposure to skyglow. We found no significant effects of direct artificial light at night on local abundance, species richness, or assemblage composition. Skyglow did not alter moth abundance or diversity at regional spatial scales. Null results were consistent across both light traps and bait traps, despite each method catching distinct moth assemblages. Though there were no overall assemblage differences driven by direct artificial light at night, we did identify a single species, Anisoneura salebrosa, as an indicator of dark habitats. We suggest that in regions with a long history of urbanization, community filtering from long-term artificial light at night exposure and intensive land-use may have already taken place. Consequently, cities like Hong Kong could offer a preview of future insect biodiversity in the developing tropics. Methods: Moths were captured using a combination of Pennsylvania light traps and fruit-baited traps across nine sites. Treatments were "lit" and "dark" (Lit: both trap types placed under a streetlamp vs. dark: both trap types placed in a nearby dark area). All sites varied in their exposure to skyglow. Trapping was conducted from June to November 2021. Data Description: MothCommunity: species abundance matrix (event x morphospecies) SiteInfo: Environmental variables and sampling details MothTaxonomy: Complete taxonomic information of each morphospecies within MothCommunity [see README for more details]